Affine Near-Semirings Over Brandt Semigroups

In order to study the structure of A ⁺(B _n )—the affine near-semiring over a Brandt semigroup—this work completely characterizes the Green's classes of its semigroup reducts. In this connection, this work classifies the elements of A ⁺(B _n ) and reports the size of A ⁺(B _n ). Further, idempotents and regular elements of the semigroup reducts of A ⁺(B _n ) have also been characterized and studied some relevant semigroups in A ⁺(B _n ).     

Affine Connection Complexes

Affine connections of 1-forms, rather than vector fields, induce complexes that project to the de Rham complexes of the underlying manifolds. This observation provides short direct proofs of Bianchi identities, existence and uniqueness of Levi-Civita connections, and symmetries of the Riemann curvature tensor.     

Polytopal Affine Semigroups with Holes Deep Inside

Given a positive integer $k$ k , we construct a lattice $3$ 3 -simplex $P$ P with the following property: The affine semigroup $Q_P$ Q P associated to $P$ P is not normal, and every element $q \in \overline{Q}_P \setminus Q_P$ q ∈ Q ¯ P ? Q P has lattice distance at least $k$ k above every facet of $Q_P$ Q P .     

生灭矩阵生成压缩半群的条件

研究了生灭矩阵本身何时在l1空间中存成压缩半群,并获得一个充要条件。     

Lp Contraction Semigroups for Vector Valued Functions

Let be a contraction semigroup on the space of vector valued functions ( is a Hilbert space). In order to study the extension of to a contaction semigroup on , Shigekawa [Sh] studied recently the domination property where is a symmetric sub-Markovian semigroup on . He gives in the setting of square field operators sufficient conditions for the above inequality. The aim of the present paper is to show that the methods of [12] and [13] can be applied in the present setting and provide two ways for the extension of to We give necessary and sufficient conditions in terms of sesquilinear forms for the contractivity property as well as for the above domination property in a more general situation.     

Generalized Affine Functions and Generalized Differentials

We study some classes of generalized affine functions, using a generalized differential. We study some properties and characterizations of these classes and we devise some characterizations of solution sets of optimization problems involving such functions or functions of related classes.     

Generating Sets of Completely 0-Simple Semigroups

ABSTRACT

A formula for the rank of an arbitrary finite completely 0-simple semigroup, represented as a Rees matrix semigroup ?⁰[G; I, Λ; P], is given. The result generalizes that of Ru?kuc concerning the rank of connected finite completely 0-simple semigroups. The rank is expressed in terms of |I|, |Λ|, the number of connected components k of P, and a number r _min, which we define. We go on to show that the number r _min is expressible in terms of a family of subgroups of G, the members of which are in one-to-one correspondence with, and determined by the nonzero entries of, the components of P. A number of applications are given, including a generalization of a result of Gomes and Howie concerning the rank of an arbitrary Brandt semigroup B(G,{1,…,n}).     

非Lipschitz仿射映射的半拓扑半群的强遍历定理(英)

本文在Banach空间中给出了非Lipschitzian仿信射拓扑半群的强遍历定理。     

On the Log-Laplace Equation for Nonlocal Operators Generating Sub-Markovian Semigroups

We consider the semilinear Cauchy problem for a class of pseudo-differential operators generating sub-Markovian semigroups. Solutions of such problems with negative definite nonlinearity play an important role in constructing branching measure-valued processes. We establish local existence and uniqueness of solutions in the context of the Dirichlet space associated to the problem. Comparison and global properties of solutions are also studied. Accepted 29 August 2001. Online publication 17 December 2001.     

Bilinear Generating Functions for Orthogonal Polynomials

Using realizations of the positive discrete series representations of the Lie algebra su(1,1) in terms of Meixner—Pollaczek polynomials, the action of su(1,1) on Poisson kernels of these polynomials is considered. In the tensor product of two such representations, two sets of eigenfunctions of a certain operator can be considered and they are shown to be related through continuous Hahn polynomials. As a result, a bilinear generating function for continuous Hahn polynomials is obtained involving the Poisson kernel of Meixner—Pollaczek polynomials; this result is also known as the Burchnall—Chaundy formula. For the positive discrete series representations of the quantized universal enveloping algebra U _q (su(1,1)) a similar analysis is performed and leads to a bilinear generating function for Askey—Wilson polynomials involving the Poisson kernel of Al-Salam and Chihara polynomials. July 6, 1997. Date accepted: September 23, 1998.     

正则解析半群与正则Cosine函数

在本文中，我们的主要结果是：若Ａ是一个正则解析半群的生成元，则Ａ也一定是某正则Ｃｏｓｉｎｅ函数的生成元．     

Markov Transition Functions and Semigroups of Measures

The application of operator semigroups to Markov processes is extended to Markov transition functions which do not have the Feller property. Markov transition functions are characterized as solutions of forward and backward equations which involve the generators of integrated semigroups and are shown to induce integral semigroups on spaces of measures.     

Symmetric Functions and Generating Functions for Descents and Major Indices in Compositions

In [18], Mendes and Remmel showed how Gessel’s generating function for the distributions of the number of descents, the major index, and the number of inversions of permutations in the symmetric group could be derived by applying a ring homomorphism defined on the ring of symmetric functions to a simple symmetric function identity. We show how similar methods may be used to prove analogues of that generating function for compositions.     

Small Semigroups Generating Varieties with Continuum Many Subvarieties

The smallest finitely based semigroup currently known to generate a variety with continuum many subvarieties is of order seven. The present article introduces a new example of order six and comments on the possibility of the existence of a smaller example. It is shown that if such an example exists, then up to isomorphism and anti-isomorphism, it must be a unique monoid of order five.     

Generating Functions for Spherical Harmonics and Spherical Monogenics

In this paper, we study generating functions for the standard orthogonal bases of spherical harmonics and spherical monogenics in \({\mathbb{R}^{m}}\) . Here spherical monogenics are polynomial solutions of the Dirac equation in \({\mathbb{R}^{m}}\) . In particular, we obtain the recurrence formula which expresses the generating function in dimension m in terms of that in dimension m–1. Hence we can find closed formulæ of generating functions in \({\mathbb{R}^{m}}\) by induction on the dimension m.     

Universal Affine Classification of Boolean Functions

In this paper we advance a practical solution of the classification problem of Boolean functions by the affine group – the largest group of linear transformations of variables. We show that the affine types (equivalence classes) can be arranged in a unique infinite sequence which contains all previous lists of types. The types are specified by their minimal representatives, spectral invariants, and stabilizer orders. A brief survey of the fundamental transformation groups is included.     

Neighborhood Complexes of Stable Kneser Graphs

It is shown that the neighborhood complexes of a family of vertex critical subgraphs of Kneser graphs—the stable Kneser graphs introduced by L. Schrijver—are spheres up to homotopy. Furthermore, it is shown that the neighborhood complexes of a subclass of the stable Kneser graphs contain the boundaries of associahedra (simplicial complexes encoding triangulations of a polygon) as a strong deformation retract.* The first author was partially supported by the Göran Gustafsson Foundation for Research in Natural Sciences and Medicine. The second author was supported by the graduate school Algorithmische Diskrete Mathematik, which is funded by the Deutsche Forschungsgemeinschaft, grant GRK 219/3. The DAAD partially supported a stay at KTH, Stockholm, in December 1998, where this work was done: DAAD program AZ 313/S-PPP